The invention herein relates to an automobile steering wheel switch comprising several individual switches and a support housing located inside the steering wheel for the accommodation of an airbag module, by means of which at least one horn switch can be activated.
DE Auslegeschrift 2,810,790 discloses a switch unit with a support housing, which is installed on a steering column tube and which accommodates different individual switches, each having its own electrical leads or a separate harness. Each individual switch has spring-like adjoining projections, which are guided in grooves of the support housing and are held in position by means of clip connections. The support housing comprises a spring-biased horn contact, which is connected on the steering column tube side over another line with a crimped-on contact element. The electrical circuit is closed over a ground connection on the steering wheel. During assembly of the steering wheel care must be taken that the connection of the horn contact is not interrupted. The individual electrical connections for the individual switches and the horn contact are relatively expensive and increase the possibilities for errors during assembly and repair of the switch unit.
Furthermore, DE 1,655,117 A1 discloses a steering column switch comprising a switch housing, which accommodates one individual switch as well as an ignition lock. The individual switch is powered by means of a supply line passed through a channel-like hollow space of the switch housing. In order to establish the electrical connection, the steering column switch is provided with a socket member terminating the appropriate supply line, whereby the individual switch has a matching plug member. In addition, a separate ground cable is provided in connection with a ball bearing mounted in a non-rotatable manner on the housing. The ignition lock is connected by means of another plug connection of the appropriate power supply line. The electrical connections require separate supply lines that pass through the steering wheel switch housing and must be installed in the latter, thereby requiring increased assembly efforts.
In order to mount an airbag module in the front central section of a steering wheel, this module is frequently associated with the support housing of the steering column switch. The activation elements for a horn switch are located either in an adjacent area of the airbag module, which is disadvantageous because the horn is not activated in time in critical situations and because the horn-activating element must be located first, or these activation elements are configured as an impact-absorbing steering wheel cap, which covers the airbag module and which is used for activation of the horn switch. This arrangement requires complex wiring of the electrical connections of the horn switch.